Duplicator master sheet clamp and control means therefor



Dec. 23, 1952 w. E. DENISON ET AL 2,622,517

DUPLICATOR MASTER SHEET CLAMP AND CONTROL MEANS THEREFOR Filed Sept. 2, 1947 3 Sheets-Sheet 1 INVENTORS w/zajfiegzzaoiz 6" 6/3 27%4/72/2261" Dec. 23, 1952 w. E. DENISON ET AL DUPLICATOR MASTER SHEET CLAMP AND CONTROL MEANS THEREFOR 3 Sheets-Sheet 2 Filed Sept. 2, 1947 INVENTORfi. Zi/Z ijezzzl's ozz/ g/a j $222M)" WAZW Dec. 23, 1952 w. E. DENISON ET AL 2,622,517

DUPLICATOR MASTER SHEET CLAMP AND CONTROL MEANS THEREFOR Filed Sept. 2, 1947 3 Sheets-Sheet 5 L I N VEN TORS 772 -27 26 2215072 6' ea Z w//2i2Z6/' Patented Dec. 23, 1952 DUPLICATOR MASTER SHEET CLAMP AND CONTROL MEANS THEREFOR William E. Denison and Glen E. Wimmer, Chicago, Ill., assignors t Speed-O-Print Corporation, Chicago, 111., a corporation of Illinois Application September 2, 1947, Serial No. 771,754

2 Claims. 1

This invention relates to a duplicating machine and mor particularly to a master clamp for such machine for securing a master impression sheet or the like to the rotatable drum or equivalent movable element thereof.

One known form of duplicating machine comprises a base or support in which a drum is rotatably carried for duplicating the letters or other characters of a master sheet carried by the drum. This master sheet must be removable from the drum so as to permit the substitution of other master sheets. It is desirable that the means for securing master sheets to the drum be as simple and as easily operable as possible. Known constructions provide such master clamps but most of these ar of a complicated nature or are carried entirely by the drum, which latter characteristic results in excessive inertia in the drum and general unbalance of the machine in operation.

The present invention contemplates and has for a principal object the provision of a master clamp that is simple in construction, asily operable, and consisting of lightweight components, part of which are carried by the drum for securing the master sheet and part of which are carried by the base or support and serving as actuating or control means for the clamping means proper.

Other objects of the invention are: to provide an improved clamping means consisting of a bail member having its bight portion disposed in a longitudinal peripheral groove in the drum for cooperation with an edge portion of the groove or slot to secure one end of a master sheet; to simplify the construction as much as possible by mounting the legs of the bail member on the drum shaft; to provide a simple rockshaft and cam mechanism for releasing the clamping action of the bail; to provide quickly operable actuating means for effecting movement of the rockshaft to release the bail; and to incorporate in the foregoing structure means serving temporarily to lock or hold the drum against rotation while master sheets are being changed.

The foregoing and other objects and features of the invention are made clear in the following detailed description of a preferred embodiment of the invention as shown in the accompanying sheets of drawings in which:

Fig. 1 is an end elevation, partly in section, of the forward portion of a duplicating machine;

Fig. 2 is a transverse sectional view taken generally along the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary plan view of one side portion of the machine showing the components of the master clamp mechanism;

Fig. 4 is a sectional view taken at one end of the drum and master clamp means as viewed along the line 4-4 of Fig. 3 and showing the master clamp means in clamping position; v

Fig. 5 is a view similar to that of Fig. 4. but showing the master clamp means in its released position.

Insofar as the general structure of the duplicating machine shown herein is concerned, the design is substantially conventional. It will be understood of course that neither the general structure of the machine nor the details of the preferred embodiment of the master clamp are to be construed as limiting the application of the invention to machines of different types or as limiting the invention to the exact details of the master clamp mechanism set forth.

The machine chosen for the purposes of illustration and description comprises generally a base It provided adjacent its forward or delivery end with right-hand and left-hand upstanding walls or supporting portions II and [2. These walls journal opposite ends of a drum shaft 13. The manner of supporting the shaft I3 in the walls II and I2 forms no part of the invention and has not therefore been illustrated or described in detail. A drum I4 is carried by the shaft l3 for rotation therewith in the direction of the arrows shown in the drawings. Paper on which copies are to be made is fed toward the drum from a suitable tray or table (not shown) at the rear end of the machine (or left-hand end as viewed in Fig. 1). Sheets of paper are fed individually between a pair of feed rollers l5 and thence between the outer periphery of the drum l4 and a cooperating pressure roller IS. The drum carries thereon a master impression sheet, the characters on which are transferred in a well known manner to the sheets passing between the drum I4 and roller IS. The sheets are delivered to the forward or right-hand end of the machine onto a receiving table or tray, a portion of which is indicated at I! in Fig. 1.

The drum I 4 is in the form of a hollow cylinder, preferably formed of sheet metal, and provided with a longitudinal peripheral slot It. The drum is mounted at its opposite ends on the shaft l3 by a pair of axially spaced flanged discs [9, each of which is preferably welded or otherwise secured to the inner periphery of the drum. The shaft I3 is provided with a right-hand collar 20 and a left-hand collar 2| which are associated with the discs l9 to fixedly support the drum on the shaft I3. The shaft l3 extends at the righthand side of the machine and is provided with a crank 22 by means of which the drum [4 is rotated.

The improved clamping means comprises a first clamping element in the form of a bail 23 having a pair of legs 24 and a transverse bight portion 25. The bail is mounted in the drum with the bightportion thereof fittin loosely in the slot I8 of the drum and with the legs 24 ex-- tending radially inwardly of the drum and pivotally or rockably carried on the drum axis by means of the collars 20 and 2|. The position of the bight 25 of the bail in the slot l8 of the drum is such that the bight form's generally a continuation of the periphery of the drum. The bail is maintained in position to engage one edge of the slot l8 and cooperate therewith to provide a clamp for clamping one marginal edge E of a master impression sheet as indicated at 26 in Fig. 4. The remainder of the master sheet is wrapped about the drum and, in the particular construction illustrated, the trailing edge of the master sheet is not clamped to the drum. The bail is maintained in clamping engagement with the master sheet 26 by means of a pair of tension springs 21 (only one of which is shown; see Figs. 4 and one end of each of which is connected to an ear on the bail 23 and the other end of each of which is connected to a stud or pin 28 carried by the proximate drum disc I9.

The means for releasing the bail 23 so that it moves from the position shown in Fig. 4 to that shown in Fig. 5 comprises operating mechanism including a transverse rockshaft 29 journaled at its opposite ends in the drum discs I9. Each end of the rocks-haft 29 extends through its proximate disc l9 and carries rigidly thereon an operating cam 30 having an inclined cam surface cooperable with an inclined surface 3| on the proximate leg 24 of the bail 23. The left-hand end of the rockshaft is provided with a crank arm 32 at the crank end of which is mounted a roller 33. A stud 34 is carried by the left-hand cam 39 and extends radially therefrom to provide means for connecting one end of a tension spring 35. The other end of the sprin is connected to a pin or stud 33 carried on the outside face of the left-hand drum disc l9. The action of the spring 35 is such as to maintain the rockshaft 29 in the position shown in Fig. 4. A pin 31 is carried by and protrudes from the left-hand leg 24 of the ball 23 and serves as a stop for limiting upward movement of the crank arm 32 of the rockshaft 29.

The structure thus far described is mounted wholly on the drum i4 and rotates therewith. This structure is light in weight and does not materially add to the rotating inertia of the drum.

The mechanism for operating the rockshaft 29 to release the bail 23 from the clamping engagement with the master sheet 26 is carried wholly by the base or support; thus, the weight 'of the actuating parts is not added to the drum. The actuating or control mechanism comprises a manually operable lever 38 and an actuating arm or cam 39. The arm or cam 39 is generally arcuate in shape and is pivoted at its lower end on a pivot pin 40 carried by a boss 4| projecting inwardly from the interior of the left-hand wall I 2. The arm 39 and mounting thereof are shown in dot-dash lines in Fig. 2, having been so illustrated because the section through the mechanism is such that these parts would not be shown. As best shown in Figs. 2 and 3, the left-hand wall structure l2 includes an exterior wall portion 42 provided with an inwardly projecting flange 43, the upper portion of which is arcuate to conform to the general contour of the wall. The mounting of the arm 39 is such that it is housed within the arcuate portion of this flange 43 and the flange 43 is cut out at 44 so that the operating lever may extend therethrough and be connected to the arm 39. The lever 38 is pivoted at 45 on a boss 49 (Fig. 3) carried by the interior of the vertical wall portion 42 of the left-hand wall or support [2.

The inner arcuate edge of the arm or cam 39 is provided with an arcuate cutout or notch 41 engageable with the roller 33 on the rockshaft 29 when the arm 39 is moved inwardly to effect release of the clamping action on the master sheet 25. A tension spring 48 is connected at one end to a tail portion 49 on the arm 39 and at its other end to a pin 50 carried by a boss 5! mounted on the interior of the wall structure 12. The action of the spring 48 is such as to urge the arm 39 to its position as shown in Fig. 4.

The upper portion of the arm 39 is provided with an angled slot 52 having a substantially long portion 53 and a relatively short or hooked portion54. The actuating lever 38 includes a nose portion 55 arranged interiorly of the flange 43 on the left-hand wall l2 and this nose portion carries a pin 56 engageable with the slot 52 in the arm 39. Durin operation of the machine the position of the lever 38 is that shown in Fig. 4. A bumper or pad 51 of flexible material is carried by the flange 43 of the left-hand wall I2 and serves as a'stop for the lever 38 in its locked or normal position.

Operation When it is desired to release the clamping action of the bail 23 for the mounting of a master sheet on the drum [4, the operating lever 38 is lifted from its position shown in Fig. 4. The pin 56 in the lever 38 will then travel along the long portion 53 of the slot 52, causing movement of the arm 39 inwardly so that the notch 41 engages the roller 33 on the crank 32 of the rockshaft 29. Continued upward movement of the lever 38 causes the arm 39 to depress the crank arm of the rockshaft and rocking of the rockshaft and cam 3| swings the bail 23 in a clockwise direction (as viewed in Figs. 4 and 5). Dur mg the end phase of the liftin of the lever 38 the pin 59 on the nose 55 thereof passes into the short or hooked portion 54 of the slot 52 in the arm 39. The parts in this position effect a lock which maintains the arm 39 in the position of Fig. 5. Since the rockshaft 29 is carried by the drum l4 and since the roller 33 on the rockshaft is lockably engaged with the notch 47 in the arm 39, it follows that the drum l 4 will be held against rotation during the changing of master sheets. Thls is an important feature of the invention, inasmuch as changing of sheets is facilitated.

The marginal edge of the master sheet 26 is 4 inserted in the space provided between the proximate edges of the drum slot l8 and the bight 25 of the bail 23 (Fig. 5). The lever 38 is then depressed, causing return of the parts to the positions of Fig. 4. As previously explained, the springs 21 and 35 maintain the clamping positions of the bail 23and rockshaft 29 and the spring 48 maintains the arm 39 in its retracted position so that it is free of engagement with the roller 33 on the rockshaft 29.

Another valuable feature of the structure just described resides in the ability of the arm 39 to locate the drum for sheet-changing. The arm 39 may be partially depressed while the rotative position of the drum and the bail 23 thereon is other than that shown in Figs. 4 and 5. The drum may then be rotated by hand until the roller 33 on the rockshaft 29 partially enters the notch 47, whereupon the arm 38 may be fully raised, with the result above set forth.

Various other objects, features and advantages of the invention set forth herein will be recognized by those skilled in the art. It will be understood of course that only a preferred embodiment of the invention has been illustrated and described and that numerous modifications and alterations may be made therein without departure from the spirit and scope of the invention set forth in the appended claims.

What is claimed is: V

1. In a duplicating machine, the combination of: a, frame; a drum rotatably carried by said frame, the periphery of said drum having a master-sheet-receiving seat extending axially of said drum; a clamp member; means mounting said clamp member on the drum for movement toward and away from said seat wherefore said seat is serviceable as a clamping complement of said clamp member; means yieldably urging said clamp member into clamping relation with said seat to clamp a master sheet onto the drums; and drum-control means including a follower element mounted on the drum and alternatively advanceable and retractible, means through which said follower element is operable when advanced to move the clamping member away from said seat, means limiting the advancement of said follower element, a locking member mounted on said frame for alternate advance and retraction thereon, said locking member having a notch receivable of the follower element to retain the follower element advanced to said limit while the locking member is advanced and while the follower element is in said notch, the sides of 6 said notch being operable through the follower element to constrain the drum against rotation in either direction, and means on said frame for releasably retaining the locking member advanced.

2. In a duplicating machine, the combination of a base; duplicating means on the base including an element carried for cyclic movement; releasable clamp means on the element for securing a master sheet thereto; release means wholly on the element and operable to release the clamp means, and including a movable arm having a portion projecting toward the base; actuating means wholly on the base and normally positioned clear of engagement with the release means and free from interference with cyclic movement of the element; means mounting the actuating means for movement to engage the release means to effect clamp-release action thereof; and means associated with the actuating means and operable, concurrently with movement thereof to clamp-release position, to engage the aforesaid projecting portion of the release means for holding the element against movement; and means for releasably locking the actuating means in the clamp-release position.

WILLIAM E. DENISON. GLEN E. WIMME-R.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,990,349 Ritzerfeld Feb. 5, 1935 2,083,043 Storck June 8, 1937 2,141,407 Ritzerfeld Dec. 27, 938 2,277,967 Gibson Mar. 31, 1942 2,374,039 Rockhill Apr. 17, 1945 2,380,744 Ford July 31, 1945 2,417,572 Storck et a1 Mar. 18, 1947 

